While concrete is really strong and can be used as a great foundation for buildings, bridges, dams, and many other things, it can't always stand up to all the stresses that are going to be placed on it as part of doing its job. There is a way to make sure that the concrete can handle the stresses to the best of its ability and can do its job safely. That is to pre-stress the concrete using post-tensioning.
Post-tensioning uses metal cables that can be pulled and anchored at the ends of the concrete. Doing that helps to reset the stresses that the concrete will take and give it the extra oomph necessary to hold up a house, parking garage, or bridge. Post-tensioning is done after the concrete has been poured and set. Without the tension, the concrete before the load will be level, but once the load is set on it, it will sag. With the tension, the concrete may look like it's slightly bowed up, but once the load has been set on it, the weight, pressure, and stress of the load will make sure that it stays level.
Post-tensioning may sound like it's a long and drawn-out process, but the fact is that it isn't that bad. The way it works is that the contractor sets the molds for the concrete slab or slaps to be poured. Inside those molds, there are also going to be tubes placed. In those tubes are going to be heavy duty metal cables. Those cables will be long enough that they stick out at either end of the concrete mold. Then the slab is cast. How thick the slab is, depends on what it is going to be used for. For example, the slab in your home may only be a few inches thick, while the slab for a parking garage may be a foot or more thicker. The concrete is going to need to dry and set before tensioning can happen. Depending on the thickness of the concrete, that can take a few days to a couple of weeks. Once the concrete is fully set and ready, the contractor will start the tensioning process. They will pull on the cables until they are at the proper stress level and then anchor them to the ends of the concrete to help keep the cables under tension. That may take a few days as well.
Post-tensioning and pre-stressing the concrete may sound like it's going to damage the concrete, but the fact is, it makes the concrete stronger. To learn more, contact a company like Advanced Post-Tension, LLC.